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Dependencies:   F7_Ethernet WebSocketClient mbed mcp3008

Fork of Nucleo_F746ZG_Ethernet by Dieter Graef

F7_Ethernet/lwip/core/ipv4/ip_frag.c@0:f9b6112278fe, 2016-06-18 (annotated)

Committer:
DieterGraef
Date:
Sat Jun 18 10:49:12 2016 +0000
Revision:
0:f9b6112278fe
Ethernet for the NUCLEO STM32F746 Board Testprogram uses DHCP and NTP to set the clock

Who changed what in which revision?

UserRevisionLine numberNew contents of line
DieterGraef 0:f9b6112278fe 1 /**
DieterGraef 0:f9b6112278fe 2 * @file
DieterGraef 0:f9b6112278fe 3 * This is the IPv4 packet segmentation and reassembly implementation.
DieterGraef 0:f9b6112278fe 4 *
DieterGraef 0:f9b6112278fe 5 */
DieterGraef 0:f9b6112278fe 6
DieterGraef 0:f9b6112278fe 7 /*
DieterGraef 0:f9b6112278fe 8 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
DieterGraef 0:f9b6112278fe 9 * All rights reserved.
DieterGraef 0:f9b6112278fe 10 *
DieterGraef 0:f9b6112278fe 11 * Redistribution and use in source and binary forms, with or without modification,
DieterGraef 0:f9b6112278fe 12 * are permitted provided that the following conditions are met:
DieterGraef 0:f9b6112278fe 13 *
DieterGraef 0:f9b6112278fe 14 * 1. Redistributions of source code must retain the above copyright notice,
DieterGraef 0:f9b6112278fe 15 * this list of conditions and the following disclaimer.
DieterGraef 0:f9b6112278fe 16 * 2. Redistributions in binary form must reproduce the above copyright notice,
DieterGraef 0:f9b6112278fe 17 * this list of conditions and the following disclaimer in the documentation
DieterGraef 0:f9b6112278fe 18 * and/or other materials provided with the distribution.
DieterGraef 0:f9b6112278fe 19 * 3. The name of the author may not be used to endorse or promote products
DieterGraef 0:f9b6112278fe 20 * derived from this software without specific prior written permission.
DieterGraef 0:f9b6112278fe 21 *
DieterGraef 0:f9b6112278fe 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
DieterGraef 0:f9b6112278fe 23 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
DieterGraef 0:f9b6112278fe 24 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
DieterGraef 0:f9b6112278fe 25 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
DieterGraef 0:f9b6112278fe 26 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
DieterGraef 0:f9b6112278fe 27 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
DieterGraef 0:f9b6112278fe 28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
DieterGraef 0:f9b6112278fe 29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
DieterGraef 0:f9b6112278fe 30 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
DieterGraef 0:f9b6112278fe 31 * OF SUCH DAMAGE.
DieterGraef 0:f9b6112278fe 32 *
DieterGraef 0:f9b6112278fe 33 * This file is part of the lwIP TCP/IP stack.
DieterGraef 0:f9b6112278fe 34 *
DieterGraef 0:f9b6112278fe 35 * Author: Jani Monoses <jani@iv.ro>
DieterGraef 0:f9b6112278fe 36 * Simon Goldschmidt
DieterGraef 0:f9b6112278fe 37 * original reassembly code by Adam Dunkels <adam@sics.se>
DieterGraef 0:f9b6112278fe 38 *
DieterGraef 0:f9b6112278fe 39 */
DieterGraef 0:f9b6112278fe 40
DieterGraef 0:f9b6112278fe 41 #include "lwip/opt.h"
DieterGraef 0:f9b6112278fe 42 #include "lwip/ip_frag.h"
DieterGraef 0:f9b6112278fe 43 #include "lwip/def.h"
DieterGraef 0:f9b6112278fe 44 #include "lwip/inet_chksum.h"
DieterGraef 0:f9b6112278fe 45 #include "lwip/netif.h"
DieterGraef 0:f9b6112278fe 46 #include "lwip/snmp.h"
DieterGraef 0:f9b6112278fe 47 #include "lwip/stats.h"
DieterGraef 0:f9b6112278fe 48 #include "lwip/icmp.h"
DieterGraef 0:f9b6112278fe 49
DieterGraef 0:f9b6112278fe 50 #include <string.h>
DieterGraef 0:f9b6112278fe 51
DieterGraef 0:f9b6112278fe 52 #if IP_REASSEMBLY
DieterGraef 0:f9b6112278fe 53 /**
DieterGraef 0:f9b6112278fe 54 * The IP reassembly code currently has the following limitations:
DieterGraef 0:f9b6112278fe 55 * - IP header options are not supported
DieterGraef 0:f9b6112278fe 56 * - fragments must not overlap (e.g. due to different routes),
DieterGraef 0:f9b6112278fe 57 * currently, overlapping or duplicate fragments are thrown away
DieterGraef 0:f9b6112278fe 58 * if IP_REASS_CHECK_OVERLAP=1 (the default)!
DieterGraef 0:f9b6112278fe 59 *
DieterGraef 0:f9b6112278fe 60 * @todo: work with IP header options
DieterGraef 0:f9b6112278fe 61 */
DieterGraef 0:f9b6112278fe 62
DieterGraef 0:f9b6112278fe 63 /** Setting this to 0, you can turn off checking the fragments for overlapping
DieterGraef 0:f9b6112278fe 64 * regions. The code gets a little smaller. Only use this if you know that
DieterGraef 0:f9b6112278fe 65 * overlapping won't occur on your network! */
DieterGraef 0:f9b6112278fe 66 #ifndef IP_REASS_CHECK_OVERLAP
DieterGraef 0:f9b6112278fe 67 #define IP_REASS_CHECK_OVERLAP 1
DieterGraef 0:f9b6112278fe 68 #endif /* IP_REASS_CHECK_OVERLAP */
DieterGraef 0:f9b6112278fe 69
DieterGraef 0:f9b6112278fe 70 /** Set to 0 to prevent freeing the oldest datagram when the reassembly buffer is
DieterGraef 0:f9b6112278fe 71 * full (IP_REASS_MAX_PBUFS pbufs are enqueued). The code gets a little smaller.
DieterGraef 0:f9b6112278fe 72 * Datagrams will be freed by timeout only. Especially useful when MEMP_NUM_REASSDATA
DieterGraef 0:f9b6112278fe 73 * is set to 1, so one datagram can be reassembled at a time, only. */
DieterGraef 0:f9b6112278fe 74 #ifndef IP_REASS_FREE_OLDEST
DieterGraef 0:f9b6112278fe 75 #define IP_REASS_FREE_OLDEST 1
DieterGraef 0:f9b6112278fe 76 #endif /* IP_REASS_FREE_OLDEST */
DieterGraef 0:f9b6112278fe 77
DieterGraef 0:f9b6112278fe 78 #define IP_REASS_FLAG_LASTFRAG 0x01
DieterGraef 0:f9b6112278fe 79
DieterGraef 0:f9b6112278fe 80 /** This is a helper struct which holds the starting
DieterGraef 0:f9b6112278fe 81 * offset and the ending offset of this fragment to
DieterGraef 0:f9b6112278fe 82 * easily chain the fragments.
DieterGraef 0:f9b6112278fe 83 * It has the same packing requirements as the IP header, since it replaces
DieterGraef 0:f9b6112278fe 84 * the IP header in memory in incoming fragments (after copying it) to keep
DieterGraef 0:f9b6112278fe 85 * track of the various fragments. (-> If the IP header doesn't need packing,
DieterGraef 0:f9b6112278fe 86 * this struct doesn't need packing, too.)
DieterGraef 0:f9b6112278fe 87 */
DieterGraef 0:f9b6112278fe 88 #ifdef PACK_STRUCT_USE_INCLUDES
DieterGraef 0:f9b6112278fe 89 # include "arch/bpstruct.h"
DieterGraef 0:f9b6112278fe 90 #endif
DieterGraef 0:f9b6112278fe 91 PACK_STRUCT_BEGIN
DieterGraef 0:f9b6112278fe 92 struct ip_reass_helper {
DieterGraef 0:f9b6112278fe 93 PACK_STRUCT_FIELD(struct pbuf *next_pbuf);
DieterGraef 0:f9b6112278fe 94 PACK_STRUCT_FIELD(u16_t start);
DieterGraef 0:f9b6112278fe 95 PACK_STRUCT_FIELD(u16_t end);
DieterGraef 0:f9b6112278fe 96 } PACK_STRUCT_STRUCT;
DieterGraef 0:f9b6112278fe 97 PACK_STRUCT_END
DieterGraef 0:f9b6112278fe 98 #ifdef PACK_STRUCT_USE_INCLUDES
DieterGraef 0:f9b6112278fe 99 # include "arch/epstruct.h"
DieterGraef 0:f9b6112278fe 100 #endif
DieterGraef 0:f9b6112278fe 101
DieterGraef 0:f9b6112278fe 102 #define IP_ADDRESSES_AND_ID_MATCH(iphdrA, iphdrB) \
DieterGraef 0:f9b6112278fe 103 (ip_addr_cmp(&(iphdrA)->src, &(iphdrB)->src) && \
DieterGraef 0:f9b6112278fe 104 ip_addr_cmp(&(iphdrA)->dest, &(iphdrB)->dest) && \
DieterGraef 0:f9b6112278fe 105 IPH_ID(iphdrA) == IPH_ID(iphdrB)) ? 1 : 0
DieterGraef 0:f9b6112278fe 106
DieterGraef 0:f9b6112278fe 107 /* global variables */
DieterGraef 0:f9b6112278fe 108 static struct ip_reassdata *reassdatagrams;
DieterGraef 0:f9b6112278fe 109 static u16_t ip_reass_pbufcount;
DieterGraef 0:f9b6112278fe 110
DieterGraef 0:f9b6112278fe 111 /* function prototypes */
DieterGraef 0:f9b6112278fe 112 static void ip_reass_dequeue_datagram(struct ip_reassdata *ipr, struct ip_reassdata *prev);
DieterGraef 0:f9b6112278fe 113 static int ip_reass_free_complete_datagram(struct ip_reassdata *ipr, struct ip_reassdata *prev);
DieterGraef 0:f9b6112278fe 114
DieterGraef 0:f9b6112278fe 115 /**
DieterGraef 0:f9b6112278fe 116 * Reassembly timer base function
DieterGraef 0:f9b6112278fe 117 * for both NO_SYS == 0 and 1 (!).
DieterGraef 0:f9b6112278fe 118 *
DieterGraef 0:f9b6112278fe 119 * Should be called every 1000 msec (defined by IP_TMR_INTERVAL).
DieterGraef 0:f9b6112278fe 120 */
DieterGraef 0:f9b6112278fe 121 void
DieterGraef 0:f9b6112278fe 122 ip_reass_tmr(void)
DieterGraef 0:f9b6112278fe 123 {
DieterGraef 0:f9b6112278fe 124 struct ip_reassdata *r, *prev = NULL;
DieterGraef 0:f9b6112278fe 125
DieterGraef 0:f9b6112278fe 126 r = reassdatagrams;
DieterGraef 0:f9b6112278fe 127 while (r != NULL) {
DieterGraef 0:f9b6112278fe 128 /* Decrement the timer. Once it reaches 0,
DieterGraef 0:f9b6112278fe 129 * clean up the incomplete fragment assembly */
DieterGraef 0:f9b6112278fe 130 if (r->timer > 0) {
DieterGraef 0:f9b6112278fe 131 r->timer--;
DieterGraef 0:f9b6112278fe 132 LWIP_DEBUGF(IP_REASS_DEBUG, ("ip_reass_tmr: timer dec %"U16_F"\n",(u16_t)r->timer));
DieterGraef 0:f9b6112278fe 133 prev = r;
DieterGraef 0:f9b6112278fe 134 r = r->next;
DieterGraef 0:f9b6112278fe 135 } else {
DieterGraef 0:f9b6112278fe 136 /* reassembly timed out */
DieterGraef 0:f9b6112278fe 137 struct ip_reassdata *tmp;
DieterGraef 0:f9b6112278fe 138 LWIP_DEBUGF(IP_REASS_DEBUG, ("ip_reass_tmr: timer timed out\n"));
DieterGraef 0:f9b6112278fe 139 tmp = r;
DieterGraef 0:f9b6112278fe 140 /* get the next pointer before freeing */
DieterGraef 0:f9b6112278fe 141 r = r->next;
DieterGraef 0:f9b6112278fe 142 /* free the helper struct and all enqueued pbufs */
DieterGraef 0:f9b6112278fe 143 ip_reass_free_complete_datagram(tmp, prev);
DieterGraef 0:f9b6112278fe 144 }
DieterGraef 0:f9b6112278fe 145 }
DieterGraef 0:f9b6112278fe 146 }
DieterGraef 0:f9b6112278fe 147
DieterGraef 0:f9b6112278fe 148 /**
DieterGraef 0:f9b6112278fe 149 * Free a datagram (struct ip_reassdata) and all its pbufs.
DieterGraef 0:f9b6112278fe 150 * Updates the total count of enqueued pbufs (ip_reass_pbufcount),
DieterGraef 0:f9b6112278fe 151 * SNMP counters and sends an ICMP time exceeded packet.
DieterGraef 0:f9b6112278fe 152 *
DieterGraef 0:f9b6112278fe 153 * @param ipr datagram to free
DieterGraef 0:f9b6112278fe 154 * @param prev the previous datagram in the linked list
DieterGraef 0:f9b6112278fe 155 * @return the number of pbufs freed
DieterGraef 0:f9b6112278fe 156 */
DieterGraef 0:f9b6112278fe 157 static int
DieterGraef 0:f9b6112278fe 158 ip_reass_free_complete_datagram(struct ip_reassdata *ipr, struct ip_reassdata *prev)
DieterGraef 0:f9b6112278fe 159 {
DieterGraef 0:f9b6112278fe 160 u16_t pbufs_freed = 0;
DieterGraef 0:f9b6112278fe 161 u8_t clen;
DieterGraef 0:f9b6112278fe 162 struct pbuf *p;
DieterGraef 0:f9b6112278fe 163 struct ip_reass_helper *iprh;
DieterGraef 0:f9b6112278fe 164
DieterGraef 0:f9b6112278fe 165 LWIP_ASSERT("prev != ipr", prev != ipr);
DieterGraef 0:f9b6112278fe 166 if (prev != NULL) {
DieterGraef 0:f9b6112278fe 167 LWIP_ASSERT("prev->next == ipr", prev->next == ipr);
DieterGraef 0:f9b6112278fe 168 }
DieterGraef 0:f9b6112278fe 169
DieterGraef 0:f9b6112278fe 170 snmp_inc_ipreasmfails();
DieterGraef 0:f9b6112278fe 171 #if LWIP_ICMP
DieterGraef 0:f9b6112278fe 172 iprh = (struct ip_reass_helper *)ipr->p->payload;
DieterGraef 0:f9b6112278fe 173 if (iprh->start == 0) {
DieterGraef 0:f9b6112278fe 174 /* The first fragment was received, send ICMP time exceeded. */
DieterGraef 0:f9b6112278fe 175 /* First, de-queue the first pbuf from r->p. */
DieterGraef 0:f9b6112278fe 176 p = ipr->p;
DieterGraef 0:f9b6112278fe 177 ipr->p = iprh->next_pbuf;
DieterGraef 0:f9b6112278fe 178 /* Then, copy the original header into it. */
DieterGraef 0:f9b6112278fe 179 SMEMCPY(p->payload, &ipr->iphdr, IP_HLEN);
DieterGraef 0:f9b6112278fe 180 icmp_time_exceeded(p, ICMP_TE_FRAG);
DieterGraef 0:f9b6112278fe 181 clen = pbuf_clen(p);
DieterGraef 0:f9b6112278fe 182 LWIP_ASSERT("pbufs_freed + clen <= 0xffff", pbufs_freed + clen <= 0xffff);
DieterGraef 0:f9b6112278fe 183 pbufs_freed += clen;
DieterGraef 0:f9b6112278fe 184 pbuf_free(p);
DieterGraef 0:f9b6112278fe 185 }
DieterGraef 0:f9b6112278fe 186 #endif /* LWIP_ICMP */
DieterGraef 0:f9b6112278fe 187
DieterGraef 0:f9b6112278fe 188 /* First, free all received pbufs. The individual pbufs need to be released
DieterGraef 0:f9b6112278fe 189 separately as they have not yet been chained */
DieterGraef 0:f9b6112278fe 190 p = ipr->p;
DieterGraef 0:f9b6112278fe 191 while (p != NULL) {
DieterGraef 0:f9b6112278fe 192 struct pbuf *pcur;
DieterGraef 0:f9b6112278fe 193 iprh = (struct ip_reass_helper *)p->payload;
DieterGraef 0:f9b6112278fe 194 pcur = p;
DieterGraef 0:f9b6112278fe 195 /* get the next pointer before freeing */
DieterGraef 0:f9b6112278fe 196 p = iprh->next_pbuf;
DieterGraef 0:f9b6112278fe 197 clen = pbuf_clen(pcur);
DieterGraef 0:f9b6112278fe 198 LWIP_ASSERT("pbufs_freed + clen <= 0xffff", pbufs_freed + clen <= 0xffff);
DieterGraef 0:f9b6112278fe 199 pbufs_freed += clen;
DieterGraef 0:f9b6112278fe 200 pbuf_free(pcur);
DieterGraef 0:f9b6112278fe 201 }
DieterGraef 0:f9b6112278fe 202 /* Then, unchain the struct ip_reassdata from the list and free it. */
DieterGraef 0:f9b6112278fe 203 ip_reass_dequeue_datagram(ipr, prev);
DieterGraef 0:f9b6112278fe 204 LWIP_ASSERT("ip_reass_pbufcount >= clen", ip_reass_pbufcount >= pbufs_freed);
DieterGraef 0:f9b6112278fe 205 ip_reass_pbufcount -= pbufs_freed;
DieterGraef 0:f9b6112278fe 206
DieterGraef 0:f9b6112278fe 207 return pbufs_freed;
DieterGraef 0:f9b6112278fe 208 }
DieterGraef 0:f9b6112278fe 209
DieterGraef 0:f9b6112278fe 210 #if IP_REASS_FREE_OLDEST
DieterGraef 0:f9b6112278fe 211 /**
DieterGraef 0:f9b6112278fe 212 * Free the oldest datagram to make room for enqueueing new fragments.
DieterGraef 0:f9b6112278fe 213 * The datagram 'fraghdr' belongs to is not freed!
DieterGraef 0:f9b6112278fe 214 *
DieterGraef 0:f9b6112278fe 215 * @param fraghdr IP header of the current fragment
DieterGraef 0:f9b6112278fe 216 * @param pbufs_needed number of pbufs needed to enqueue
DieterGraef 0:f9b6112278fe 217 * (used for freeing other datagrams if not enough space)
DieterGraef 0:f9b6112278fe 218 * @return the number of pbufs freed
DieterGraef 0:f9b6112278fe 219 */
DieterGraef 0:f9b6112278fe 220 static int
DieterGraef 0:f9b6112278fe 221 ip_reass_remove_oldest_datagram(struct ip_hdr *fraghdr, int pbufs_needed)
DieterGraef 0:f9b6112278fe 222 {
DieterGraef 0:f9b6112278fe 223 /* @todo Can't we simply remove the last datagram in the
DieterGraef 0:f9b6112278fe 224 * linked list behind reassdatagrams?
DieterGraef 0:f9b6112278fe 225 */
DieterGraef 0:f9b6112278fe 226 struct ip_reassdata *r, *oldest, *prev;
DieterGraef 0:f9b6112278fe 227 int pbufs_freed = 0, pbufs_freed_current;
DieterGraef 0:f9b6112278fe 228 int other_datagrams;
DieterGraef 0:f9b6112278fe 229
DieterGraef 0:f9b6112278fe 230 /* Free datagrams until being allowed to enqueue 'pbufs_needed' pbufs,
DieterGraef 0:f9b6112278fe 231 * but don't free the datagram that 'fraghdr' belongs to! */
DieterGraef 0:f9b6112278fe 232 do {
DieterGraef 0:f9b6112278fe 233 oldest = NULL;
DieterGraef 0:f9b6112278fe 234 prev = NULL;
DieterGraef 0:f9b6112278fe 235 other_datagrams = 0;
DieterGraef 0:f9b6112278fe 236 r = reassdatagrams;
DieterGraef 0:f9b6112278fe 237 while (r != NULL) {
DieterGraef 0:f9b6112278fe 238 if (!IP_ADDRESSES_AND_ID_MATCH(&r->iphdr, fraghdr)) {
DieterGraef 0:f9b6112278fe 239 /* Not the same datagram as fraghdr */
DieterGraef 0:f9b6112278fe 240 other_datagrams++;
DieterGraef 0:f9b6112278fe 241 if (oldest == NULL) {
DieterGraef 0:f9b6112278fe 242 oldest = r;
DieterGraef 0:f9b6112278fe 243 } else if (r->timer <= oldest->timer) {
DieterGraef 0:f9b6112278fe 244 /* older than the previous oldest */
DieterGraef 0:f9b6112278fe 245 oldest = r;
DieterGraef 0:f9b6112278fe 246 }
DieterGraef 0:f9b6112278fe 247 }
DieterGraef 0:f9b6112278fe 248 if (r->next != NULL) {
DieterGraef 0:f9b6112278fe 249 prev = r;
DieterGraef 0:f9b6112278fe 250 }
DieterGraef 0:f9b6112278fe 251 r = r->next;
DieterGraef 0:f9b6112278fe 252 }
DieterGraef 0:f9b6112278fe 253 if (oldest != NULL) {
DieterGraef 0:f9b6112278fe 254 pbufs_freed_current = ip_reass_free_complete_datagram(oldest, prev);
DieterGraef 0:f9b6112278fe 255 pbufs_freed += pbufs_freed_current;
DieterGraef 0:f9b6112278fe 256 }
DieterGraef 0:f9b6112278fe 257 } while ((pbufs_freed < pbufs_needed) && (other_datagrams > 1));
DieterGraef 0:f9b6112278fe 258 return pbufs_freed;
DieterGraef 0:f9b6112278fe 259 }
DieterGraef 0:f9b6112278fe 260 #endif /* IP_REASS_FREE_OLDEST */
DieterGraef 0:f9b6112278fe 261
DieterGraef 0:f9b6112278fe 262 /**
DieterGraef 0:f9b6112278fe 263 * Enqueues a new fragment into the fragment queue
DieterGraef 0:f9b6112278fe 264 * @param fraghdr points to the new fragments IP hdr
DieterGraef 0:f9b6112278fe 265 * @param clen number of pbufs needed to enqueue (used for freeing other datagrams if not enough space)
DieterGraef 0:f9b6112278fe 266 * @return A pointer to the queue location into which the fragment was enqueued
DieterGraef 0:f9b6112278fe 267 */
DieterGraef 0:f9b6112278fe 268 static struct ip_reassdata*
DieterGraef 0:f9b6112278fe 269 ip_reass_enqueue_new_datagram(struct ip_hdr *fraghdr, int clen)
DieterGraef 0:f9b6112278fe 270 {
DieterGraef 0:f9b6112278fe 271 struct ip_reassdata* ipr;
DieterGraef 0:f9b6112278fe 272 /* No matching previous fragment found, allocate a new reassdata struct */
DieterGraef 0:f9b6112278fe 273 ipr = (struct ip_reassdata *)memp_malloc(MEMP_REASSDATA);
DieterGraef 0:f9b6112278fe 274 if (ipr == NULL) {
DieterGraef 0:f9b6112278fe 275 #if IP_REASS_FREE_OLDEST
DieterGraef 0:f9b6112278fe 276 if (ip_reass_remove_oldest_datagram(fraghdr, clen) >= clen) {
DieterGraef 0:f9b6112278fe 277 ipr = (struct ip_reassdata *)memp_malloc(MEMP_REASSDATA);
DieterGraef 0:f9b6112278fe 278 }
DieterGraef 0:f9b6112278fe 279 if (ipr == NULL)
DieterGraef 0:f9b6112278fe 280 #endif /* IP_REASS_FREE_OLDEST */
DieterGraef 0:f9b6112278fe 281 {
DieterGraef 0:f9b6112278fe 282 IPFRAG_STATS_INC(ip_frag.memerr);
DieterGraef 0:f9b6112278fe 283 LWIP_DEBUGF(IP_REASS_DEBUG,("Failed to alloc reassdata struct\n"));
DieterGraef 0:f9b6112278fe 284 return NULL;
DieterGraef 0:f9b6112278fe 285 }
DieterGraef 0:f9b6112278fe 286 }
DieterGraef 0:f9b6112278fe 287 memset(ipr, 0, sizeof(struct ip_reassdata));
DieterGraef 0:f9b6112278fe 288 ipr->timer = IP_REASS_MAXAGE;
DieterGraef 0:f9b6112278fe 289
DieterGraef 0:f9b6112278fe 290 /* enqueue the new structure to the front of the list */
DieterGraef 0:f9b6112278fe 291 ipr->next = reassdatagrams;
DieterGraef 0:f9b6112278fe 292 reassdatagrams = ipr;
DieterGraef 0:f9b6112278fe 293 /* copy the ip header for later tests and input */
DieterGraef 0:f9b6112278fe 294 /* @todo: no ip options supported? */
DieterGraef 0:f9b6112278fe 295 SMEMCPY(&(ipr->iphdr), fraghdr, IP_HLEN);
DieterGraef 0:f9b6112278fe 296 return ipr;
DieterGraef 0:f9b6112278fe 297 }
DieterGraef 0:f9b6112278fe 298
DieterGraef 0:f9b6112278fe 299 /**
DieterGraef 0:f9b6112278fe 300 * Dequeues a datagram from the datagram queue. Doesn't deallocate the pbufs.
DieterGraef 0:f9b6112278fe 301 * @param ipr points to the queue entry to dequeue
DieterGraef 0:f9b6112278fe 302 */
DieterGraef 0:f9b6112278fe 303 static void
DieterGraef 0:f9b6112278fe 304 ip_reass_dequeue_datagram(struct ip_reassdata *ipr, struct ip_reassdata *prev)
DieterGraef 0:f9b6112278fe 305 {
DieterGraef 0:f9b6112278fe 306
DieterGraef 0:f9b6112278fe 307 /* dequeue the reass struct */
DieterGraef 0:f9b6112278fe 308 if (reassdatagrams == ipr) {
DieterGraef 0:f9b6112278fe 309 /* it was the first in the list */
DieterGraef 0:f9b6112278fe 310 reassdatagrams = ipr->next;
DieterGraef 0:f9b6112278fe 311 } else {
DieterGraef 0:f9b6112278fe 312 /* it wasn't the first, so it must have a valid 'prev' */
DieterGraef 0:f9b6112278fe 313 LWIP_ASSERT("sanity check linked list", prev != NULL);
DieterGraef 0:f9b6112278fe 314 prev->next = ipr->next;
DieterGraef 0:f9b6112278fe 315 }
DieterGraef 0:f9b6112278fe 316
DieterGraef 0:f9b6112278fe 317 /* now we can free the ip_reass struct */
DieterGraef 0:f9b6112278fe 318 memp_free(MEMP_REASSDATA, ipr);
DieterGraef 0:f9b6112278fe 319 }
DieterGraef 0:f9b6112278fe 320
DieterGraef 0:f9b6112278fe 321 /**
DieterGraef 0:f9b6112278fe 322 * Chain a new pbuf into the pbuf list that composes the datagram. The pbuf list
DieterGraef 0:f9b6112278fe 323 * will grow over time as new pbufs are rx.
DieterGraef 0:f9b6112278fe 324 * Also checks that the datagram passes basic continuity checks (if the last
DieterGraef 0:f9b6112278fe 325 * fragment was received at least once).
DieterGraef 0:f9b6112278fe 326 * @param root_p points to the 'root' pbuf for the current datagram being assembled.
DieterGraef 0:f9b6112278fe 327 * @param new_p points to the pbuf for the current fragment
DieterGraef 0:f9b6112278fe 328 * @return 0 if invalid, >0 otherwise
DieterGraef 0:f9b6112278fe 329 */
DieterGraef 0:f9b6112278fe 330 static int
DieterGraef 0:f9b6112278fe 331 ip_reass_chain_frag_into_datagram_and_validate(struct ip_reassdata *ipr, struct pbuf *new_p)
DieterGraef 0:f9b6112278fe 332 {
DieterGraef 0:f9b6112278fe 333 struct ip_reass_helper *iprh, *iprh_tmp, *iprh_prev=NULL;
DieterGraef 0:f9b6112278fe 334 struct pbuf *q;
DieterGraef 0:f9b6112278fe 335 u16_t offset,len;
DieterGraef 0:f9b6112278fe 336 struct ip_hdr *fraghdr;
DieterGraef 0:f9b6112278fe 337 int valid = 1;
DieterGraef 0:f9b6112278fe 338
DieterGraef 0:f9b6112278fe 339 /* Extract length and fragment offset from current fragment */
DieterGraef 0:f9b6112278fe 340 fraghdr = (struct ip_hdr*)new_p->payload;
DieterGraef 0:f9b6112278fe 341 len = ntohs(IPH_LEN(fraghdr)) - IPH_HL(fraghdr) * 4;
DieterGraef 0:f9b6112278fe 342 offset = (ntohs(IPH_OFFSET(fraghdr)) & IP_OFFMASK) * 8;
DieterGraef 0:f9b6112278fe 343
DieterGraef 0:f9b6112278fe 344 /* overwrite the fragment's ip header from the pbuf with our helper struct,
DieterGraef 0:f9b6112278fe 345 * and setup the embedded helper structure. */
DieterGraef 0:f9b6112278fe 346 /* make sure the struct ip_reass_helper fits into the IP header */
DieterGraef 0:f9b6112278fe 347 LWIP_ASSERT("sizeof(struct ip_reass_helper) <= IP_HLEN",
DieterGraef 0:f9b6112278fe 348 sizeof(struct ip_reass_helper) <= IP_HLEN);
DieterGraef 0:f9b6112278fe 349 iprh = (struct ip_reass_helper*)new_p->payload;
DieterGraef 0:f9b6112278fe 350 iprh->next_pbuf = NULL;
DieterGraef 0:f9b6112278fe 351 iprh->start = offset;
DieterGraef 0:f9b6112278fe 352 iprh->end = offset + len;
DieterGraef 0:f9b6112278fe 353
DieterGraef 0:f9b6112278fe 354 /* Iterate through until we either get to the end of the list (append),
DieterGraef 0:f9b6112278fe 355 * or we find on with a larger offset (insert). */
DieterGraef 0:f9b6112278fe 356 for (q = ipr->p; q != NULL;) {
DieterGraef 0:f9b6112278fe 357 iprh_tmp = (struct ip_reass_helper*)q->payload;
DieterGraef 0:f9b6112278fe 358 if (iprh->start < iprh_tmp->start) {
DieterGraef 0:f9b6112278fe 359 /* the new pbuf should be inserted before this */
DieterGraef 0:f9b6112278fe 360 iprh->next_pbuf = q;
DieterGraef 0:f9b6112278fe 361 if (iprh_prev != NULL) {
DieterGraef 0:f9b6112278fe 362 /* not the fragment with the lowest offset */
DieterGraef 0:f9b6112278fe 363 #if IP_REASS_CHECK_OVERLAP
DieterGraef 0:f9b6112278fe 364 if ((iprh->start < iprh_prev->end) || (iprh->end > iprh_tmp->start)) {
DieterGraef 0:f9b6112278fe 365 /* fragment overlaps with previous or following, throw away */
DieterGraef 0:f9b6112278fe 366 goto freepbuf;
DieterGraef 0:f9b6112278fe 367 }
DieterGraef 0:f9b6112278fe 368 #endif /* IP_REASS_CHECK_OVERLAP */
DieterGraef 0:f9b6112278fe 369 iprh_prev->next_pbuf = new_p;
DieterGraef 0:f9b6112278fe 370 } else {
DieterGraef 0:f9b6112278fe 371 /* fragment with the lowest offset */
DieterGraef 0:f9b6112278fe 372 ipr->p = new_p;
DieterGraef 0:f9b6112278fe 373 }
DieterGraef 0:f9b6112278fe 374 break;
DieterGraef 0:f9b6112278fe 375 } else if(iprh->start == iprh_tmp->start) {
DieterGraef 0:f9b6112278fe 376 /* received the same datagram twice: no need to keep the datagram */
DieterGraef 0:f9b6112278fe 377 goto freepbuf;
DieterGraef 0:f9b6112278fe 378 #if IP_REASS_CHECK_OVERLAP
DieterGraef 0:f9b6112278fe 379 } else if(iprh->start < iprh_tmp->end) {
DieterGraef 0:f9b6112278fe 380 /* overlap: no need to keep the new datagram */
DieterGraef 0:f9b6112278fe 381 goto freepbuf;
DieterGraef 0:f9b6112278fe 382 #endif /* IP_REASS_CHECK_OVERLAP */
DieterGraef 0:f9b6112278fe 383 } else {
DieterGraef 0:f9b6112278fe 384 /* Check if the fragments received so far have no wholes. */
DieterGraef 0:f9b6112278fe 385 if (iprh_prev != NULL) {
DieterGraef 0:f9b6112278fe 386 if (iprh_prev->end != iprh_tmp->start) {
DieterGraef 0:f9b6112278fe 387 /* There is a fragment missing between the current
DieterGraef 0:f9b6112278fe 388 * and the previous fragment */
DieterGraef 0:f9b6112278fe 389 valid = 0;
DieterGraef 0:f9b6112278fe 390 }
DieterGraef 0:f9b6112278fe 391 }
DieterGraef 0:f9b6112278fe 392 }
DieterGraef 0:f9b6112278fe 393 q = iprh_tmp->next_pbuf;
DieterGraef 0:f9b6112278fe 394 iprh_prev = iprh_tmp;
DieterGraef 0:f9b6112278fe 395 }
DieterGraef 0:f9b6112278fe 396
DieterGraef 0:f9b6112278fe 397 /* If q is NULL, then we made it to the end of the list. Determine what to do now */
DieterGraef 0:f9b6112278fe 398 if (q == NULL) {
DieterGraef 0:f9b6112278fe 399 if (iprh_prev != NULL) {
DieterGraef 0:f9b6112278fe 400 /* this is (for now), the fragment with the highest offset:
DieterGraef 0:f9b6112278fe 401 * chain it to the last fragment */
DieterGraef 0:f9b6112278fe 402 #if IP_REASS_CHECK_OVERLAP
DieterGraef 0:f9b6112278fe 403 LWIP_ASSERT("check fragments don't overlap", iprh_prev->end <= iprh->start);
DieterGraef 0:f9b6112278fe 404 #endif /* IP_REASS_CHECK_OVERLAP */
DieterGraef 0:f9b6112278fe 405 iprh_prev->next_pbuf = new_p;
DieterGraef 0:f9b6112278fe 406 if (iprh_prev->end != iprh->start) {
DieterGraef 0:f9b6112278fe 407 valid = 0;
DieterGraef 0:f9b6112278fe 408 }
DieterGraef 0:f9b6112278fe 409 } else {
DieterGraef 0:f9b6112278fe 410 #if IP_REASS_CHECK_OVERLAP
DieterGraef 0:f9b6112278fe 411 LWIP_ASSERT("no previous fragment, this must be the first fragment!",
DieterGraef 0:f9b6112278fe 412 ipr->p == NULL);
DieterGraef 0:f9b6112278fe 413 #endif /* IP_REASS_CHECK_OVERLAP */
DieterGraef 0:f9b6112278fe 414 /* this is the first fragment we ever received for this ip datagram */
DieterGraef 0:f9b6112278fe 415 ipr->p = new_p;
DieterGraef 0:f9b6112278fe 416 }
DieterGraef 0:f9b6112278fe 417 }
DieterGraef 0:f9b6112278fe 418
DieterGraef 0:f9b6112278fe 419 /* At this point, the validation part begins: */
DieterGraef 0:f9b6112278fe 420 /* If we already received the last fragment */
DieterGraef 0:f9b6112278fe 421 if ((ipr->flags & IP_REASS_FLAG_LASTFRAG) != 0) {
DieterGraef 0:f9b6112278fe 422 /* and had no wholes so far */
DieterGraef 0:f9b6112278fe 423 if (valid) {
DieterGraef 0:f9b6112278fe 424 /* then check if the rest of the fragments is here */
DieterGraef 0:f9b6112278fe 425 /* Check if the queue starts with the first datagram */
DieterGraef 0:f9b6112278fe 426 if (((struct ip_reass_helper*)ipr->p->payload)->start != 0) {
DieterGraef 0:f9b6112278fe 427 valid = 0;
DieterGraef 0:f9b6112278fe 428 } else {
DieterGraef 0:f9b6112278fe 429 /* and check that there are no wholes after this datagram */
DieterGraef 0:f9b6112278fe 430 iprh_prev = iprh;
DieterGraef 0:f9b6112278fe 431 q = iprh->next_pbuf;
DieterGraef 0:f9b6112278fe 432 while (q != NULL) {
DieterGraef 0:f9b6112278fe 433 iprh = (struct ip_reass_helper*)q->payload;
DieterGraef 0:f9b6112278fe 434 if (iprh_prev->end != iprh->start) {
DieterGraef 0:f9b6112278fe 435 valid = 0;
DieterGraef 0:f9b6112278fe 436 break;
DieterGraef 0:f9b6112278fe 437 }
DieterGraef 0:f9b6112278fe 438 iprh_prev = iprh;
DieterGraef 0:f9b6112278fe 439 q = iprh->next_pbuf;
DieterGraef 0:f9b6112278fe 440 }
DieterGraef 0:f9b6112278fe 441 /* if still valid, all fragments are received
DieterGraef 0:f9b6112278fe 442 * (because to the MF==0 already arrived */
DieterGraef 0:f9b6112278fe 443 if (valid) {
DieterGraef 0:f9b6112278fe 444 LWIP_ASSERT("sanity check", ipr->p != NULL);
DieterGraef 0:f9b6112278fe 445 LWIP_ASSERT("sanity check",
DieterGraef 0:f9b6112278fe 446 ((struct ip_reass_helper*)ipr->p->payload) != iprh);
DieterGraef 0:f9b6112278fe 447 LWIP_ASSERT("validate_datagram:next_pbuf!=NULL",
DieterGraef 0:f9b6112278fe 448 iprh->next_pbuf == NULL);
DieterGraef 0:f9b6112278fe 449 LWIP_ASSERT("validate_datagram:datagram end!=datagram len",
DieterGraef 0:f9b6112278fe 450 iprh->end == ipr->datagram_len);
DieterGraef 0:f9b6112278fe 451 }
DieterGraef 0:f9b6112278fe 452 }
DieterGraef 0:f9b6112278fe 453 }
DieterGraef 0:f9b6112278fe 454 /* If valid is 0 here, there are some fragments missing in the middle
DieterGraef 0:f9b6112278fe 455 * (since MF == 0 has already arrived). Such datagrams simply time out if
DieterGraef 0:f9b6112278fe 456 * no more fragments are received... */
DieterGraef 0:f9b6112278fe 457 return valid;
DieterGraef 0:f9b6112278fe 458 }
DieterGraef 0:f9b6112278fe 459 /* If we come here, not all fragments were received, yet! */
DieterGraef 0:f9b6112278fe 460 return 0; /* not yet valid! */
DieterGraef 0:f9b6112278fe 461 #if IP_REASS_CHECK_OVERLAP
DieterGraef 0:f9b6112278fe 462 freepbuf:
DieterGraef 0:f9b6112278fe 463 ip_reass_pbufcount -= pbuf_clen(new_p);
DieterGraef 0:f9b6112278fe 464 pbuf_free(new_p);
DieterGraef 0:f9b6112278fe 465 return 0;
DieterGraef 0:f9b6112278fe 466 #endif /* IP_REASS_CHECK_OVERLAP */
DieterGraef 0:f9b6112278fe 467 }
DieterGraef 0:f9b6112278fe 468
DieterGraef 0:f9b6112278fe 469 /**
DieterGraef 0:f9b6112278fe 470 * Reassembles incoming IP fragments into an IP datagram.
DieterGraef 0:f9b6112278fe 471 *
DieterGraef 0:f9b6112278fe 472 * @param p points to a pbuf chain of the fragment
DieterGraef 0:f9b6112278fe 473 * @return NULL if reassembly is incomplete, ? otherwise
DieterGraef 0:f9b6112278fe 474 */
DieterGraef 0:f9b6112278fe 475 struct pbuf *
DieterGraef 0:f9b6112278fe 476 ip_reass(struct pbuf *p)
DieterGraef 0:f9b6112278fe 477 {
DieterGraef 0:f9b6112278fe 478 struct pbuf *r;
DieterGraef 0:f9b6112278fe 479 struct ip_hdr *fraghdr;
DieterGraef 0:f9b6112278fe 480 struct ip_reassdata *ipr;
DieterGraef 0:f9b6112278fe 481 struct ip_reass_helper *iprh;
DieterGraef 0:f9b6112278fe 482 u16_t offset, len;
DieterGraef 0:f9b6112278fe 483 u8_t clen;
DieterGraef 0:f9b6112278fe 484 struct ip_reassdata *ipr_prev = NULL;
DieterGraef 0:f9b6112278fe 485
DieterGraef 0:f9b6112278fe 486 IPFRAG_STATS_INC(ip_frag.recv);
DieterGraef 0:f9b6112278fe 487 snmp_inc_ipreasmreqds();
DieterGraef 0:f9b6112278fe 488
DieterGraef 0:f9b6112278fe 489 fraghdr = (struct ip_hdr*)p->payload;
DieterGraef 0:f9b6112278fe 490
DieterGraef 0:f9b6112278fe 491 if ((IPH_HL(fraghdr) * 4) != IP_HLEN) {
DieterGraef 0:f9b6112278fe 492 LWIP_DEBUGF(IP_REASS_DEBUG,("ip_reass: IP options currently not supported!\n"));
DieterGraef 0:f9b6112278fe 493 IPFRAG_STATS_INC(ip_frag.err);
DieterGraef 0:f9b6112278fe 494 goto nullreturn;
DieterGraef 0:f9b6112278fe 495 }
DieterGraef 0:f9b6112278fe 496
DieterGraef 0:f9b6112278fe 497 offset = (ntohs(IPH_OFFSET(fraghdr)) & IP_OFFMASK) * 8;
DieterGraef 0:f9b6112278fe 498 len = ntohs(IPH_LEN(fraghdr)) - IPH_HL(fraghdr) * 4;
DieterGraef 0:f9b6112278fe 499
DieterGraef 0:f9b6112278fe 500 /* Check if we are allowed to enqueue more datagrams. */
DieterGraef 0:f9b6112278fe 501 clen = pbuf_clen(p);
DieterGraef 0:f9b6112278fe 502 if ((ip_reass_pbufcount + clen) > IP_REASS_MAX_PBUFS) {
DieterGraef 0:f9b6112278fe 503 #if IP_REASS_FREE_OLDEST
DieterGraef 0:f9b6112278fe 504 if (!ip_reass_remove_oldest_datagram(fraghdr, clen) ||
DieterGraef 0:f9b6112278fe 505 ((ip_reass_pbufcount + clen) > IP_REASS_MAX_PBUFS))
DieterGraef 0:f9b6112278fe 506 #endif /* IP_REASS_FREE_OLDEST */
DieterGraef 0:f9b6112278fe 507 {
DieterGraef 0:f9b6112278fe 508 /* No datagram could be freed and still too many pbufs enqueued */
DieterGraef 0:f9b6112278fe 509 LWIP_DEBUGF(IP_REASS_DEBUG,("ip_reass: Overflow condition: pbufct=%d, clen=%d, MAX=%d\n",
DieterGraef 0:f9b6112278fe 510 ip_reass_pbufcount, clen, IP_REASS_MAX_PBUFS));
DieterGraef 0:f9b6112278fe 511 IPFRAG_STATS_INC(ip_frag.memerr);
DieterGraef 0:f9b6112278fe 512 /* @todo: send ICMP time exceeded here? */
DieterGraef 0:f9b6112278fe 513 /* drop this pbuf */
DieterGraef 0:f9b6112278fe 514 goto nullreturn;
DieterGraef 0:f9b6112278fe 515 }
DieterGraef 0:f9b6112278fe 516 }
DieterGraef 0:f9b6112278fe 517
DieterGraef 0:f9b6112278fe 518 /* Look for the datagram the fragment belongs to in the current datagram queue,
DieterGraef 0:f9b6112278fe 519 * remembering the previous in the queue for later dequeueing. */
DieterGraef 0:f9b6112278fe 520 for (ipr = reassdatagrams; ipr != NULL; ipr = ipr->next) {
DieterGraef 0:f9b6112278fe 521 /* Check if the incoming fragment matches the one currently present
DieterGraef 0:f9b6112278fe 522 in the reassembly buffer. If so, we proceed with copying the
DieterGraef 0:f9b6112278fe 523 fragment into the buffer. */
DieterGraef 0:f9b6112278fe 524 if (IP_ADDRESSES_AND_ID_MATCH(&ipr->iphdr, fraghdr)) {
DieterGraef 0:f9b6112278fe 525 LWIP_DEBUGF(IP_REASS_DEBUG, ("ip_reass: matching previous fragment ID=%"X16_F"\n",
DieterGraef 0:f9b6112278fe 526 ntohs(IPH_ID(fraghdr))));
DieterGraef 0:f9b6112278fe 527 IPFRAG_STATS_INC(ip_frag.cachehit);
DieterGraef 0:f9b6112278fe 528 break;
DieterGraef 0:f9b6112278fe 529 }
DieterGraef 0:f9b6112278fe 530 ipr_prev = ipr;
DieterGraef 0:f9b6112278fe 531 }
DieterGraef 0:f9b6112278fe 532
DieterGraef 0:f9b6112278fe 533 if (ipr == NULL) {
DieterGraef 0:f9b6112278fe 534 /* Enqueue a new datagram into the datagram queue */
DieterGraef 0:f9b6112278fe 535 ipr = ip_reass_enqueue_new_datagram(fraghdr, clen);
DieterGraef 0:f9b6112278fe 536 /* Bail if unable to enqueue */
DieterGraef 0:f9b6112278fe 537 if(ipr == NULL) {
DieterGraef 0:f9b6112278fe 538 goto nullreturn;
DieterGraef 0:f9b6112278fe 539 }
DieterGraef 0:f9b6112278fe 540 } else {
DieterGraef 0:f9b6112278fe 541 if (((ntohs(IPH_OFFSET(fraghdr)) & IP_OFFMASK) == 0) &&
DieterGraef 0:f9b6112278fe 542 ((ntohs(IPH_OFFSET(&ipr->iphdr)) & IP_OFFMASK) != 0)) {
DieterGraef 0:f9b6112278fe 543 /* ipr->iphdr is not the header from the first fragment, but fraghdr is
DieterGraef 0:f9b6112278fe 544 * -> copy fraghdr into ipr->iphdr since we want to have the header
DieterGraef 0:f9b6112278fe 545 * of the first fragment (for ICMP time exceeded and later, for copying
DieterGraef 0:f9b6112278fe 546 * all options, if supported)*/
DieterGraef 0:f9b6112278fe 547 SMEMCPY(&ipr->iphdr, fraghdr, IP_HLEN);
DieterGraef 0:f9b6112278fe 548 }
DieterGraef 0:f9b6112278fe 549 }
DieterGraef 0:f9b6112278fe 550 /* Track the current number of pbufs current 'in-flight', in order to limit
DieterGraef 0:f9b6112278fe 551 the number of fragments that may be enqueued at any one time */
DieterGraef 0:f9b6112278fe 552 ip_reass_pbufcount += clen;
DieterGraef 0:f9b6112278fe 553
DieterGraef 0:f9b6112278fe 554 /* At this point, we have either created a new entry or pointing
DieterGraef 0:f9b6112278fe 555 * to an existing one */
DieterGraef 0:f9b6112278fe 556
DieterGraef 0:f9b6112278fe 557 /* check for 'no more fragments', and update queue entry*/
DieterGraef 0:f9b6112278fe 558 if ((IPH_OFFSET(fraghdr) & PP_NTOHS(IP_MF)) == 0) {
DieterGraef 0:f9b6112278fe 559 ipr->flags |= IP_REASS_FLAG_LASTFRAG;
DieterGraef 0:f9b6112278fe 560 ipr->datagram_len = offset + len;
DieterGraef 0:f9b6112278fe 561 LWIP_DEBUGF(IP_REASS_DEBUG,
DieterGraef 0:f9b6112278fe 562 ("ip_reass: last fragment seen, total len %"S16_F"\n",
DieterGraef 0:f9b6112278fe 563 ipr->datagram_len));
DieterGraef 0:f9b6112278fe 564 }
DieterGraef 0:f9b6112278fe 565 /* find the right place to insert this pbuf */
DieterGraef 0:f9b6112278fe 566 /* @todo: trim pbufs if fragments are overlapping */
DieterGraef 0:f9b6112278fe 567 if (ip_reass_chain_frag_into_datagram_and_validate(ipr, p)) {
DieterGraef 0:f9b6112278fe 568 /* the totally last fragment (flag more fragments = 0) was received at least
DieterGraef 0:f9b6112278fe 569 * once AND all fragments are received */
DieterGraef 0:f9b6112278fe 570 ipr->datagram_len += IP_HLEN;
DieterGraef 0:f9b6112278fe 571
DieterGraef 0:f9b6112278fe 572 /* save the second pbuf before copying the header over the pointer */
DieterGraef 0:f9b6112278fe 573 r = ((struct ip_reass_helper*)ipr->p->payload)->next_pbuf;
DieterGraef 0:f9b6112278fe 574
DieterGraef 0:f9b6112278fe 575 /* copy the original ip header back to the first pbuf */
DieterGraef 0:f9b6112278fe 576 fraghdr = (struct ip_hdr*)(ipr->p->payload);
DieterGraef 0:f9b6112278fe 577 SMEMCPY(fraghdr, &ipr->iphdr, IP_HLEN);
DieterGraef 0:f9b6112278fe 578 IPH_LEN_SET(fraghdr, htons(ipr->datagram_len));
DieterGraef 0:f9b6112278fe 579 IPH_OFFSET_SET(fraghdr, 0);
DieterGraef 0:f9b6112278fe 580 IPH_CHKSUM_SET(fraghdr, 0);
DieterGraef 0:f9b6112278fe 581 /* @todo: do we need to set calculate the correct checksum? */
DieterGraef 0:f9b6112278fe 582 IPH_CHKSUM_SET(fraghdr, inet_chksum(fraghdr, IP_HLEN));
DieterGraef 0:f9b6112278fe 583
DieterGraef 0:f9b6112278fe 584 p = ipr->p;
DieterGraef 0:f9b6112278fe 585
DieterGraef 0:f9b6112278fe 586 /* chain together the pbufs contained within the reass_data list. */
DieterGraef 0:f9b6112278fe 587 while(r != NULL) {
DieterGraef 0:f9b6112278fe 588 iprh = (struct ip_reass_helper*)r->payload;
DieterGraef 0:f9b6112278fe 589
DieterGraef 0:f9b6112278fe 590 /* hide the ip header for every succeding fragment */
DieterGraef 0:f9b6112278fe 591 pbuf_header(r, -IP_HLEN);
DieterGraef 0:f9b6112278fe 592 pbuf_cat(p, r);
DieterGraef 0:f9b6112278fe 593 r = iprh->next_pbuf;
DieterGraef 0:f9b6112278fe 594 }
DieterGraef 0:f9b6112278fe 595 /* release the sources allocate for the fragment queue entry */
DieterGraef 0:f9b6112278fe 596 ip_reass_dequeue_datagram(ipr, ipr_prev);
DieterGraef 0:f9b6112278fe 597
DieterGraef 0:f9b6112278fe 598 /* and adjust the number of pbufs currently queued for reassembly. */
DieterGraef 0:f9b6112278fe 599 ip_reass_pbufcount -= pbuf_clen(p);
DieterGraef 0:f9b6112278fe 600
DieterGraef 0:f9b6112278fe 601 /* Return the pbuf chain */
DieterGraef 0:f9b6112278fe 602 return p;
DieterGraef 0:f9b6112278fe 603 }
DieterGraef 0:f9b6112278fe 604 /* the datagram is not (yet?) reassembled completely */
DieterGraef 0:f9b6112278fe 605 LWIP_DEBUGF(IP_REASS_DEBUG,("ip_reass_pbufcount: %d out\n", ip_reass_pbufcount));
DieterGraef 0:f9b6112278fe 606 return NULL;
DieterGraef 0:f9b6112278fe 607
DieterGraef 0:f9b6112278fe 608 nullreturn:
DieterGraef 0:f9b6112278fe 609 LWIP_DEBUGF(IP_REASS_DEBUG,("ip_reass: nullreturn\n"));
DieterGraef 0:f9b6112278fe 610 IPFRAG_STATS_INC(ip_frag.drop);
DieterGraef 0:f9b6112278fe 611 pbuf_free(p);
DieterGraef 0:f9b6112278fe 612 return NULL;
DieterGraef 0:f9b6112278fe 613 }
DieterGraef 0:f9b6112278fe 614 #endif /* IP_REASSEMBLY */
DieterGraef 0:f9b6112278fe 615
DieterGraef 0:f9b6112278fe 616 #if IP_FRAG
DieterGraef 0:f9b6112278fe 617 #if IP_FRAG_USES_STATIC_BUF
DieterGraef 0:f9b6112278fe 618 static u8_t buf[LWIP_MEM_ALIGN_SIZE(IP_FRAG_MAX_MTU + MEM_ALIGNMENT - 1)];
DieterGraef 0:f9b6112278fe 619 #else /* IP_FRAG_USES_STATIC_BUF */
DieterGraef 0:f9b6112278fe 620
DieterGraef 0:f9b6112278fe 621 #if !LWIP_NETIF_TX_SINGLE_PBUF
DieterGraef 0:f9b6112278fe 622 /** Allocate a new struct pbuf_custom_ref */
DieterGraef 0:f9b6112278fe 623 static struct pbuf_custom_ref*
DieterGraef 0:f9b6112278fe 624 ip_frag_alloc_pbuf_custom_ref(void)
DieterGraef 0:f9b6112278fe 625 {
DieterGraef 0:f9b6112278fe 626 return (struct pbuf_custom_ref*)memp_malloc(MEMP_FRAG_PBUF);
DieterGraef 0:f9b6112278fe 627 }
DieterGraef 0:f9b6112278fe 628
DieterGraef 0:f9b6112278fe 629 /** Free a struct pbuf_custom_ref */
DieterGraef 0:f9b6112278fe 630 static void
DieterGraef 0:f9b6112278fe 631 ip_frag_free_pbuf_custom_ref(struct pbuf_custom_ref* p)
DieterGraef 0:f9b6112278fe 632 {
DieterGraef 0:f9b6112278fe 633 LWIP_ASSERT("p != NULL", p != NULL);
DieterGraef 0:f9b6112278fe 634 memp_free(MEMP_FRAG_PBUF, p);
DieterGraef 0:f9b6112278fe 635 }
DieterGraef 0:f9b6112278fe 636
DieterGraef 0:f9b6112278fe 637 /** Free-callback function to free a 'struct pbuf_custom_ref', called by
DieterGraef 0:f9b6112278fe 638 * pbuf_free. */
DieterGraef 0:f9b6112278fe 639 static void
DieterGraef 0:f9b6112278fe 640 ipfrag_free_pbuf_custom(struct pbuf *p)
DieterGraef 0:f9b6112278fe 641 {
DieterGraef 0:f9b6112278fe 642 struct pbuf_custom_ref *pcr = (struct pbuf_custom_ref*)p;
DieterGraef 0:f9b6112278fe 643 LWIP_ASSERT("pcr != NULL", pcr != NULL);
DieterGraef 0:f9b6112278fe 644 LWIP_ASSERT("pcr == p", (void*)pcr == (void*)p);
DieterGraef 0:f9b6112278fe 645 if (pcr->original != NULL) {
DieterGraef 0:f9b6112278fe 646 pbuf_free(pcr->original);
DieterGraef 0:f9b6112278fe 647 }
DieterGraef 0:f9b6112278fe 648 ip_frag_free_pbuf_custom_ref(pcr);
DieterGraef 0:f9b6112278fe 649 }
DieterGraef 0:f9b6112278fe 650 #endif /* !LWIP_NETIF_TX_SINGLE_PBUF */
DieterGraef 0:f9b6112278fe 651 #endif /* IP_FRAG_USES_STATIC_BUF */
DieterGraef 0:f9b6112278fe 652
DieterGraef 0:f9b6112278fe 653 /**
DieterGraef 0:f9b6112278fe 654 * Fragment an IP datagram if too large for the netif.
DieterGraef 0:f9b6112278fe 655 *
DieterGraef 0:f9b6112278fe 656 * Chop the datagram in MTU sized chunks and send them in order
DieterGraef 0:f9b6112278fe 657 * by using a fixed size static memory buffer (PBUF_REF) or
DieterGraef 0:f9b6112278fe 658 * point PBUF_REFs into p (depending on IP_FRAG_USES_STATIC_BUF).
DieterGraef 0:f9b6112278fe 659 *
DieterGraef 0:f9b6112278fe 660 * @param p ip packet to send
DieterGraef 0:f9b6112278fe 661 * @param netif the netif on which to send
DieterGraef 0:f9b6112278fe 662 * @param dest destination ip address to which to send
DieterGraef 0:f9b6112278fe 663 *
DieterGraef 0:f9b6112278fe 664 * @return ERR_OK if sent successfully, err_t otherwise
DieterGraef 0:f9b6112278fe 665 */
DieterGraef 0:f9b6112278fe 666 err_t
DieterGraef 0:f9b6112278fe 667 ip_frag(struct pbuf *p, struct netif *netif, ip_addr_t *dest)
DieterGraef 0:f9b6112278fe 668 {
DieterGraef 0:f9b6112278fe 669 struct pbuf *rambuf;
DieterGraef 0:f9b6112278fe 670 #if IP_FRAG_USES_STATIC_BUF
DieterGraef 0:f9b6112278fe 671 struct pbuf *header;
DieterGraef 0:f9b6112278fe 672 #else
DieterGraef 0:f9b6112278fe 673 #if !LWIP_NETIF_TX_SINGLE_PBUF
DieterGraef 0:f9b6112278fe 674 struct pbuf *newpbuf;
DieterGraef 0:f9b6112278fe 675 #endif
DieterGraef 0:f9b6112278fe 676 struct ip_hdr *original_iphdr;
DieterGraef 0:f9b6112278fe 677 #endif
DieterGraef 0:f9b6112278fe 678 struct ip_hdr *iphdr;
DieterGraef 0:f9b6112278fe 679 u16_t nfb;
DieterGraef 0:f9b6112278fe 680 u16_t left, cop;
DieterGraef 0:f9b6112278fe 681 u16_t mtu = netif->mtu;
DieterGraef 0:f9b6112278fe 682 u16_t ofo, omf;
DieterGraef 0:f9b6112278fe 683 u16_t last;
DieterGraef 0:f9b6112278fe 684 u16_t poff = IP_HLEN;
DieterGraef 0:f9b6112278fe 685 u16_t tmp;
DieterGraef 0:f9b6112278fe 686 #if !IP_FRAG_USES_STATIC_BUF && !LWIP_NETIF_TX_SINGLE_PBUF
DieterGraef 0:f9b6112278fe 687 u16_t newpbuflen = 0;
DieterGraef 0:f9b6112278fe 688 u16_t left_to_copy;
DieterGraef 0:f9b6112278fe 689 #endif
DieterGraef 0:f9b6112278fe 690
DieterGraef 0:f9b6112278fe 691 /* Get a RAM based MTU sized pbuf */
DieterGraef 0:f9b6112278fe 692 #if IP_FRAG_USES_STATIC_BUF
DieterGraef 0:f9b6112278fe 693 /* When using a static buffer, we use a PBUF_REF, which we will
DieterGraef 0:f9b6112278fe 694 * use to reference the packet (without link header).
DieterGraef 0:f9b6112278fe 695 * Layer and length is irrelevant.
DieterGraef 0:f9b6112278fe 696 */
DieterGraef 0:f9b6112278fe 697 rambuf = pbuf_alloc(PBUF_LINK, 0, PBUF_REF);
DieterGraef 0:f9b6112278fe 698 if (rambuf == NULL) {
DieterGraef 0:f9b6112278fe 699 LWIP_DEBUGF(IP_REASS_DEBUG, ("ip_frag: pbuf_alloc(PBUF_LINK, 0, PBUF_REF) failed\n"));
DieterGraef 0:f9b6112278fe 700 return ERR_MEM;
DieterGraef 0:f9b6112278fe 701 }
DieterGraef 0:f9b6112278fe 702 rambuf->tot_len = rambuf->len = mtu;
DieterGraef 0:f9b6112278fe 703 rambuf->payload = LWIP_MEM_ALIGN((void *)buf);
DieterGraef 0:f9b6112278fe 704
DieterGraef 0:f9b6112278fe 705 /* Copy the IP header in it */
DieterGraef 0:f9b6112278fe 706 iphdr = (struct ip_hdr *)rambuf->payload;
DieterGraef 0:f9b6112278fe 707 SMEMCPY(iphdr, p->payload, IP_HLEN);
DieterGraef 0:f9b6112278fe 708 #else /* IP_FRAG_USES_STATIC_BUF */
DieterGraef 0:f9b6112278fe 709 original_iphdr = (struct ip_hdr *)p->payload;
DieterGraef 0:f9b6112278fe 710 iphdr = original_iphdr;
DieterGraef 0:f9b6112278fe 711 #endif /* IP_FRAG_USES_STATIC_BUF */
DieterGraef 0:f9b6112278fe 712
DieterGraef 0:f9b6112278fe 713 /* Save original offset */
DieterGraef 0:f9b6112278fe 714 tmp = ntohs(IPH_OFFSET(iphdr));
DieterGraef 0:f9b6112278fe 715 ofo = tmp & IP_OFFMASK;
DieterGraef 0:f9b6112278fe 716 omf = tmp & IP_MF;
DieterGraef 0:f9b6112278fe 717
DieterGraef 0:f9b6112278fe 718 left = p->tot_len - IP_HLEN;
DieterGraef 0:f9b6112278fe 719
DieterGraef 0:f9b6112278fe 720 nfb = (mtu - IP_HLEN) / 8;
DieterGraef 0:f9b6112278fe 721
DieterGraef 0:f9b6112278fe 722 while (left) {
DieterGraef 0:f9b6112278fe 723 last = (left <= mtu - IP_HLEN);
DieterGraef 0:f9b6112278fe 724
DieterGraef 0:f9b6112278fe 725 /* Set new offset and MF flag */
DieterGraef 0:f9b6112278fe 726 tmp = omf | (IP_OFFMASK & (ofo));
DieterGraef 0:f9b6112278fe 727 if (!last) {
DieterGraef 0:f9b6112278fe 728 tmp = tmp | IP_MF;
DieterGraef 0:f9b6112278fe 729 }
DieterGraef 0:f9b6112278fe 730
DieterGraef 0:f9b6112278fe 731 /* Fill this fragment */
DieterGraef 0:f9b6112278fe 732 cop = last ? left : nfb * 8;
DieterGraef 0:f9b6112278fe 733
DieterGraef 0:f9b6112278fe 734 #if IP_FRAG_USES_STATIC_BUF
DieterGraef 0:f9b6112278fe 735 poff += pbuf_copy_partial(p, (u8_t*)iphdr + IP_HLEN, cop, poff);
DieterGraef 0:f9b6112278fe 736 #else /* IP_FRAG_USES_STATIC_BUF */
DieterGraef 0:f9b6112278fe 737 #if LWIP_NETIF_TX_SINGLE_PBUF
DieterGraef 0:f9b6112278fe 738 rambuf = pbuf_alloc(PBUF_IP, cop, PBUF_RAM);
DieterGraef 0:f9b6112278fe 739 if (rambuf == NULL) {
DieterGraef 0:f9b6112278fe 740 return ERR_MEM;
DieterGraef 0:f9b6112278fe 741 }
DieterGraef 0:f9b6112278fe 742 LWIP_ASSERT("this needs a pbuf in one piece!",
DieterGraef 0:f9b6112278fe 743 (rambuf->len == rambuf->tot_len) && (rambuf->next == NULL));
DieterGraef 0:f9b6112278fe 744 poff += pbuf_copy_partial(p, rambuf->payload, cop, poff);
DieterGraef 0:f9b6112278fe 745 /* make room for the IP header */
DieterGraef 0:f9b6112278fe 746 if(pbuf_header(rambuf, IP_HLEN)) {
DieterGraef 0:f9b6112278fe 747 pbuf_free(rambuf);
DieterGraef 0:f9b6112278fe 748 return ERR_MEM;
DieterGraef 0:f9b6112278fe 749 }
DieterGraef 0:f9b6112278fe 750 /* fill in the IP header */
DieterGraef 0:f9b6112278fe 751 SMEMCPY(rambuf->payload, original_iphdr, IP_HLEN);
DieterGraef 0:f9b6112278fe 752 iphdr = rambuf->payload;
DieterGraef 0:f9b6112278fe 753 #else /* LWIP_NETIF_TX_SINGLE_PBUF */
DieterGraef 0:f9b6112278fe 754 /* When not using a static buffer, create a chain of pbufs.
DieterGraef 0:f9b6112278fe 755 * The first will be a PBUF_RAM holding the link and IP header.
DieterGraef 0:f9b6112278fe 756 * The rest will be PBUF_REFs mirroring the pbuf chain to be fragged,
DieterGraef 0:f9b6112278fe 757 * but limited to the size of an mtu.
DieterGraef 0:f9b6112278fe 758 */
DieterGraef 0:f9b6112278fe 759 rambuf = pbuf_alloc(PBUF_LINK, IP_HLEN, PBUF_RAM);
DieterGraef 0:f9b6112278fe 760 if (rambuf == NULL) {
DieterGraef 0:f9b6112278fe 761 return ERR_MEM;
DieterGraef 0:f9b6112278fe 762 }
DieterGraef 0:f9b6112278fe 763 LWIP_ASSERT("this needs a pbuf in one piece!",
DieterGraef 0:f9b6112278fe 764 (p->len >= (IP_HLEN)));
DieterGraef 0:f9b6112278fe 765 SMEMCPY(rambuf->payload, original_iphdr, IP_HLEN);
DieterGraef 0:f9b6112278fe 766 iphdr = (struct ip_hdr *)rambuf->payload;
DieterGraef 0:f9b6112278fe 767
DieterGraef 0:f9b6112278fe 768 /* Can just adjust p directly for needed offset. */
DieterGraef 0:f9b6112278fe 769 p->payload = (u8_t *)p->payload + poff;
DieterGraef 0:f9b6112278fe 770 p->len -= poff;
DieterGraef 0:f9b6112278fe 771
DieterGraef 0:f9b6112278fe 772 left_to_copy = cop;
DieterGraef 0:f9b6112278fe 773 while (left_to_copy) {
DieterGraef 0:f9b6112278fe 774 struct pbuf_custom_ref *pcr;
DieterGraef 0:f9b6112278fe 775 newpbuflen = (left_to_copy < p->len) ? left_to_copy : p->len;
DieterGraef 0:f9b6112278fe 776 /* Is this pbuf already empty? */
DieterGraef 0:f9b6112278fe 777 if (!newpbuflen) {
DieterGraef 0:f9b6112278fe 778 p = p->next;
DieterGraef 0:f9b6112278fe 779 continue;
DieterGraef 0:f9b6112278fe 780 }
DieterGraef 0:f9b6112278fe 781 pcr = ip_frag_alloc_pbuf_custom_ref();
DieterGraef 0:f9b6112278fe 782 if (pcr == NULL) {
DieterGraef 0:f9b6112278fe 783 pbuf_free(rambuf);
DieterGraef 0:f9b6112278fe 784 return ERR_MEM;
DieterGraef 0:f9b6112278fe 785 }
DieterGraef 0:f9b6112278fe 786 /* Mirror this pbuf, although we might not need all of it. */
DieterGraef 0:f9b6112278fe 787 newpbuf = pbuf_alloced_custom(PBUF_RAW, newpbuflen, PBUF_REF, &pcr->pc, p->payload, newpbuflen);
DieterGraef 0:f9b6112278fe 788 if (newpbuf == NULL) {
DieterGraef 0:f9b6112278fe 789 ip_frag_free_pbuf_custom_ref(pcr);
DieterGraef 0:f9b6112278fe 790 pbuf_free(rambuf);
DieterGraef 0:f9b6112278fe 791 return ERR_MEM;
DieterGraef 0:f9b6112278fe 792 }
DieterGraef 0:f9b6112278fe 793 pbuf_ref(p);
DieterGraef 0:f9b6112278fe 794 pcr->original = p;
DieterGraef 0:f9b6112278fe 795 pcr->pc.custom_free_function = ipfrag_free_pbuf_custom;
DieterGraef 0:f9b6112278fe 796
DieterGraef 0:f9b6112278fe 797 /* Add it to end of rambuf's chain, but using pbuf_cat, not pbuf_chain
DieterGraef 0:f9b6112278fe 798 * so that it is removed when pbuf_dechain is later called on rambuf.
DieterGraef 0:f9b6112278fe 799 */
DieterGraef 0:f9b6112278fe 800 pbuf_cat(rambuf, newpbuf);
DieterGraef 0:f9b6112278fe 801 left_to_copy -= newpbuflen;
DieterGraef 0:f9b6112278fe 802 if (left_to_copy) {
DieterGraef 0:f9b6112278fe 803 p = p->next;
DieterGraef 0:f9b6112278fe 804 }
DieterGraef 0:f9b6112278fe 805 }
DieterGraef 0:f9b6112278fe 806 poff = newpbuflen;
DieterGraef 0:f9b6112278fe 807 #endif /* LWIP_NETIF_TX_SINGLE_PBUF */
DieterGraef 0:f9b6112278fe 808 #endif /* IP_FRAG_USES_STATIC_BUF */
DieterGraef 0:f9b6112278fe 809
DieterGraef 0:f9b6112278fe 810 /* Correct header */
DieterGraef 0:f9b6112278fe 811 IPH_OFFSET_SET(iphdr, htons(tmp));
DieterGraef 0:f9b6112278fe 812 IPH_LEN_SET(iphdr, htons(cop + IP_HLEN));
DieterGraef 0:f9b6112278fe 813 IPH_CHKSUM_SET(iphdr, 0);
DieterGraef 0:f9b6112278fe 814 IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, IP_HLEN));
DieterGraef 0:f9b6112278fe 815
DieterGraef 0:f9b6112278fe 816 #if IP_FRAG_USES_STATIC_BUF
DieterGraef 0:f9b6112278fe 817 if (last) {
DieterGraef 0:f9b6112278fe 818 pbuf_realloc(rambuf, left + IP_HLEN);
DieterGraef 0:f9b6112278fe 819 }
DieterGraef 0:f9b6112278fe 820
DieterGraef 0:f9b6112278fe 821 /* This part is ugly: we alloc a RAM based pbuf for
DieterGraef 0:f9b6112278fe 822 * the link level header for each chunk and then
DieterGraef 0:f9b6112278fe 823 * free it.A PBUF_ROM style pbuf for which pbuf_header
DieterGraef 0:f9b6112278fe 824 * worked would make things simpler.
DieterGraef 0:f9b6112278fe 825 */
DieterGraef 0:f9b6112278fe 826 header = pbuf_alloc(PBUF_LINK, 0, PBUF_RAM);
DieterGraef 0:f9b6112278fe 827 if (header != NULL) {
DieterGraef 0:f9b6112278fe 828 pbuf_chain(header, rambuf);
DieterGraef 0:f9b6112278fe 829 netif->output(netif, header, dest);
DieterGraef 0:f9b6112278fe 830 IPFRAG_STATS_INC(ip_frag.xmit);
DieterGraef 0:f9b6112278fe 831 snmp_inc_ipfragcreates();
DieterGraef 0:f9b6112278fe 832 pbuf_free(header);
DieterGraef 0:f9b6112278fe 833 } else {
DieterGraef 0:f9b6112278fe 834 LWIP_DEBUGF(IP_REASS_DEBUG, ("ip_frag: pbuf_alloc() for header failed\n"));
DieterGraef 0:f9b6112278fe 835 pbuf_free(rambuf);
DieterGraef 0:f9b6112278fe 836 return ERR_MEM;
DieterGraef 0:f9b6112278fe 837 }
DieterGraef 0:f9b6112278fe 838 #else /* IP_FRAG_USES_STATIC_BUF */
DieterGraef 0:f9b6112278fe 839 /* No need for separate header pbuf - we allowed room for it in rambuf
DieterGraef 0:f9b6112278fe 840 * when allocated.
DieterGraef 0:f9b6112278fe 841 */
DieterGraef 0:f9b6112278fe 842 netif->output(netif, rambuf, dest);
DieterGraef 0:f9b6112278fe 843 IPFRAG_STATS_INC(ip_frag.xmit);
DieterGraef 0:f9b6112278fe 844
DieterGraef 0:f9b6112278fe 845 /* Unfortunately we can't reuse rambuf - the hardware may still be
DieterGraef 0:f9b6112278fe 846 * using the buffer. Instead we free it (and the ensuing chain) and
DieterGraef 0:f9b6112278fe 847 * recreate it next time round the loop. If we're lucky the hardware
DieterGraef 0:f9b6112278fe 848 * will have already sent the packet, the free will really free, and
DieterGraef 0:f9b6112278fe 849 * there will be zero memory penalty.
DieterGraef 0:f9b6112278fe 850 */
DieterGraef 0:f9b6112278fe 851
DieterGraef 0:f9b6112278fe 852 pbuf_free(rambuf);
DieterGraef 0:f9b6112278fe 853 #endif /* IP_FRAG_USES_STATIC_BUF */
DieterGraef 0:f9b6112278fe 854 left -= cop;
DieterGraef 0:f9b6112278fe 855 ofo += nfb;
DieterGraef 0:f9b6112278fe 856 }
DieterGraef 0:f9b6112278fe 857 #if IP_FRAG_USES_STATIC_BUF
DieterGraef 0:f9b6112278fe 858 pbuf_free(rambuf);
DieterGraef 0:f9b6112278fe 859 #endif /* IP_FRAG_USES_STATIC_BUF */
DieterGraef 0:f9b6112278fe 860 snmp_inc_ipfragoks();
DieterGraef 0:f9b6112278fe 861 return ERR_OK;
DieterGraef 0:f9b6112278fe 862 }
DieterGraef 0:f9b6112278fe 863 #endif /* IP_FRAG */